#include <iostream>
using namespace std;

void swap1(int num1,int num2) {
    int swap = num1;
    num1 = num2;
    num2 = swap;
    cout << "num1: " << num1<< endl;
    cout << "num2: " << num2<< endl;

}
int main(){
    int num1 = 10;
    int num2 = 20;
    swap1(num1,num2);
    cout << "num1: " << num1<< endl;
    cout << "num2: " << num2<< endl;

    return 0;
}